Neuroanatomy of the Aging Brain Observed in Vivo

Raz, Naftali

doi:10.1007/978-1-4899-1769-0_6

Cited by 25 publications

(16 citation statements)

References 127 publications

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“…This had previously been attributed to shrinkage of the substantia nigra (Raz, 1996), however there is sparse histopathological evidence to support this hypothesis (McCormack et al, 2004; Collier et al, 2007). Our study agrees with previous work in that brainstem aging-associated atrophy seems to be confined to the midbrain.…”

Section: Discussionmentioning

confidence: 99%

Characterizing Aging in the Human Brainstem Using Quantitative Multimodal MRI Analysis

Lambert¹,

Chowdhury²,

FitzGerald³

et al. 2013

Front. Hum. Neurosci.

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Aging is ubiquitous to the human condition. The MRI correlates of healthy aging have been extensively investigated using a range of modalities, including volumetric MRI, quantitative MRI (qMRI), and diffusion tensor imaging. Despite this, the reported brainstem related changes remain sparse. This is, in part, due to the technical and methodological limitations in quantitatively assessing and statistically analyzing this region. By utilizing a new method of brainstem segmentation, a large cohort of 100 healthy adults were assessed in this study for the effects of aging within the human brainstem in vivo. Using qMRI, tensor-based morphometry (TBM), and voxel-based quantification (VBQ), the volumetric and quantitative changes across healthy adults between 19 and 75 years were characterized. In addition to the increased R2* in substantia nigra corresponding to increasing iron deposition with age, several novel findings were reported in the current study. These include selective volumetric loss of the brachium conjunctivum, with a corresponding decrease in magnetization transfer and increase in proton density (PD), accounting for the previously described “midbrain shrinkage.” Additionally, we found increases in R1 and PD in several pontine and medullary structures. We consider these changes in the context of well-characterized, functional age-related changes, and propose potential biophysical mechanisms. This study provides detailed quantitative analysis of the internal architecture of the brainstem and provides a baseline for further studies of neurodegenerative diseases that are characterized by early, pre-clinical involvement of the brainstem, such as Parkinson’s and Alzheimer’s diseases.

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Section: Discussionmentioning

confidence: 99%

Characterizing Aging in the Human Brainstem Using Quantitative Multimodal MRI Analysis

Lambert¹,

Chowdhury²,

FitzGerald³

et al. 2013

Front. Hum. Neurosci.

View full text Add to dashboard Cite

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“…Current neuropsychological models of aging suggest that deterioration in the frontal lobes of the brain is accountable for the cognitive changes associated with healthy adult aging [34,35,39,41]. This "frontal" hypothesis of aging is based also on the observation that older people perform relatively poorly on a range of neuropsychological tests normally used to assess frontal lobe dysfunction [1,3,5,12,13,20,40].…”

Section: Introductionmentioning

confidence: 99%

The role of semantic knowledge on the cognitive estimation task

Sala

MacPherson

Phillips

et al. 2004

Journal of Neurology

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The current study investigated the role of semantic knowledge on the Cognitive Estimation Task (CET). In an initial experiment, the CET performance of 21 patients with frontal lobe lesions was compared with 21 healthy controls. The CET was found to be sensitive to the effects of frontal lobe lesions. In Experiment 2, 175 participants aged between 18 and 87 years performed the CET to examine the effects of healthy adult aging on the task. No significant age effects were evident. In Experiment 3, 27 patients with Alzheimer's disease (AD) were compared with 27 healthy controls on the CET. AD patients produced significantly more extreme cognitive estimates than the controls. A significant correlation was found between CET performance and performance on the General Knowledge of the World Task, a task intended to assess semantic knowledge. The hypothesis is put forward that healthy older adults are able to use their intact semantic knowledge to compensate for problem-solving deficits when generating cognitive estimates. In contrast, owing to degradation in semantic abilities, AD patients are unable to benefit from semantic knowledge and instead tend to produce bizarre cognitive estimates.

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“…Using brain magnetic resonance imaging (MRI), Raz (1996) and others have argued that age-related atrophy is more pronounced for the frontal lobes and basal ganglia than for the temporal, parietal, and occipital lobes of the brain. Morphological studies also suggest that the frontal cortex and corpus striatum show greater volume losses with normal aging than do the temporal, parietal, and occipital cortices (Haug, 1985).…”

Section: Introductionmentioning

confidence: 99%

Elucidating the contributions of processing speed, executive ability, and frontal lobe volume to normal age-related differences in fluid intelligence

Schretlen

Pearlson

Anthony

et al. 2000

J Int Neuropsychol Soc

171

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One theory of normal cognitive aging asserts that decreases in simple processing speed mediate the age-related decline of fluid intelligence. Another possibility is that age-related atrophic changes in frontal brain structures undermine the functioning of executive abilities, thereby producing the same decline. In this study, we used principal components analysis to derive a measure of fluid-spatial intelligence in 197 normal adults between 20 and 92 years of age. Measures of perceptual comparison speed, working memory, and executive ability, as well as regional brain volumes based on high resolution magnetic resonance imaging were obtained from a subsample of 112 participants. We then conducted a series of hierarchical multiple regression analyses to test whether (1) the processing speed theory, (2) frontal-executive theory, or (3) some combination of these best accounted for age-related variation in fluid intelligence. The results showed that perceptual comparison speed, executive ability, and frontal lobe volume each made significant contributions to a regression equation that explained 57% of the variance in fluid intelligence. These findings suggest that both the processing speed and frontal-executive theory of cognitive aging are partially correct and complement one another. (JINS, 2000, 6, 52-61.)

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Neuroanatomy of the Aging Brain Observed in Vivo

Cited by 25 publications

References 127 publications

Characterizing Aging in the Human Brainstem Using Quantitative Multimodal MRI Analysis

Characterizing Aging in the Human Brainstem Using Quantitative Multimodal MRI Analysis

The role of semantic knowledge on the cognitive estimation task

Elucidating the contributions of processing speed, executive ability, and frontal lobe volume to normal age-related differences in fluid intelligence

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